Surgical instrument and method of use for facilitating positioning of an osteochondral plug

ABSTRACT

A surgical instrument and method are provided for positioning an osteochondral plug within a bone defect site. The instrument includes an elongate shaft, a ribbon, an elongate sleeve and a locking mechanism. The shaft has proximal and distal ends, with the distal end being shaped to contact the osteochondral plug. The ribbon extends along two sides of the shaft and around the distal end, forming a loop that is used to secure the osteochondral plug to the distal end. The sleeve is movably mounted to the shaft for reciprocating relative thereto between retracted and extended positions. The sleeve includes a slot that allows for visualization and cutting of the ribbon. The locking mechanism locks the ribbon in place and thereby controls the size and tension of the loop that surrounds the osteochondral plug, securing it to the distal end of the shaft.

CROSS-REFERENCE TO RELATED APPLICATIONS/PATENTS

This application contains subject matter which is related to the subjectmatter of the following application, which is hereby incorporated hereinby reference in its entirety:

-   -   “Osteochondral Repair Assembly Including Retracting Spacer, Kit        and Method,” by Gil et al., U.S. Ser. No. 11/390,320, filed Mar.        28, 2006.

TECHNICAL FIELD

The present invention relates generally to the field of surgery andosteochondral grafting, and more particularly, to surgical instrumentsand methods for positioning an osteochondral bone plug within a defectsite of a patient.

BACKGROUND OF THE INVENTION

Human joint surfaces are covered by articular cartilage that provides aresilient, durable surface with low friction. Cartilage is an avasculartissue that has a small number of chondrocytes encapsulated within anextensive extracellular matrix. The cartilage acts to distributemechanical forces and to protect subchondral bone. The knee is aparticular instance of a cartilage surfaced (the condyle) bone area. Theknee comprises three bones—the femur, tibia, and patella that are heldin place by various ligaments. Corresponding chondral areas of the femurand the tibia form a hinge joint and the patella acts to protect thejoint. Portions of the chondral areas as well as the undersurface of thepatella are covered with articular cartilage that allows the femur,patella and tibia to smoothly glide against each other without causingdamage.

Damage to the articular cartilage, subchondral bone or both can resultfrom traumatic injury or a disease state. For example, articularcartilage in the knee can be damaged due to traumatic injury as withathletes and via a degenerative process as with older patients. The kneecartilage does not heal well due to the lack of vascularity. Hyalinecartilage in particular has a limited capacity for repair and lesions inthis material, without intervention, can form scar tissue lacking thebiomechanical properties of normal cartilage.

A number of procedures are used to treat damaged articular cartilage.Currently, the most widely used procedure involves lavage, arthroscopicdebridement and repair stimulation. Repair stimulation is conducted byseveral methods including, drilling, abrasion arthroplasty andmicrofracture. The goal of these procedures is to penetrate intosubchondral bone to induce bleeding and fibrin clot formation. Thisreaction promotes initial repair. However, the resulting formed tissueis often fibrous in nature and lacks the durability of normal articularcartilage.

Another known treatment involves the removal and replacement of thedamaged articular cartilage with a prosthetic device. However,historically, artificial prostheses have largely had limited successsince they are non-elastic, and therefore lack the shock-absorbing,properties characteristic of the normal cartilage. Moreover, the knownartificial devices have shown a reduced ability to withstand the highand complex forces inherent to routine knee joint function.

In an attempt to overcome the problems associated with the abovetechniques, osteochondral transplantation, also known as “mosaicplasty”or “OATS” has been used to repair articular cartilage. This procedureinvolves removing injured tissue from the articular defect and drillingcylindrical openings in the area of the defect and underlying bone.Cylindrical plugs, consisting of healthy cartilage overlying subchondralbone, are harvested from another area of the patient, typically from alower weight-bearing region of the joint under repair, or from a donorpatient, and are implanted in the host openings. However, in thesecases, if the opening is too large, the graft can rotate or move withinthe host site and become loose, which will prevent bio-integration withthe surrounding tissues. Further, if the host site is too small,significant tissue and cellular damage can occur to the graft during theimplantation.

Historically, osteochondral grafting has been used successfully torepair chondral damage and to replace damaged articular cartilage andsubchondral bone. First, in this procedure, cartilage and bone tissue ofa defect site are removed by routing to create a cylindrical bore of aprecise geometry. Then a cartilage and subchondral bone plug graft isharvested in a matching geometry. The donor plug graft is typicallyremoved from another body region of less strain. The donor plug graftcan be harvested from a recipient source (autograft) or from anothersuitable human or other animal donor (allograft). The harvested pluggraft is then implanted into the bore of the routed defect site. Healingof the plug graft to the host bone results in fixation of the plug graftto the surrounding host region.

Success of the grafting process is dependant on the intimate seating ofthe graft within the socket. First, surface characteristics of the pluggraft are critical. For the procedure to be successful, the surface ofthe transplanted plug graft must have the same contour as the excisedosteochondral tissue. If the contour is not a correct match, a repairedarticular surface is at risk for further damage during motion.Additionally, some graft shapes do not pack well into irregular defects.The graft may have a propensity to rotate resulting in poor integrationof the graft to the surrounding host tissue. An improperly placed pluggraft can result in host tissue integration failure and postimplantation motion.

Since the plug graft is press-fit within a recipient socket, removal orrepositioning can cause irreparable damage that can render a graftuseless. Hence, a surgeon has only one opportunity to properly press fitthe graft into the host site. If the graft is placed too shallow or toodeep or otherwise incorrectly, the graft cannot be removed for properpositioning by typical procedures or tools. Extraction procedures andtools can cause further damage to the boundary host site cells and tothe graft structural integrity.

Thus, there is a need for a surgical instrument to which a donor plugmay be secured and method of use to permit flexible donor graft plugplacement and replacement, if necessary without causing damage to thehost site or the donor plug.

SUMMARY OF THE INVENTION

The present invention comprises a surgical instrument and methods forsecuring a graft plug to an instrument, facilitating positioning of agraft plug within a bone defect and fabricating an instrument to be usedwhen implanting a bone graft plug within the body. The instrument andmethods disclosed herein employ an instrument-to-plug graft attachmentapproach that is of sufficient strength for the surgical instrument tobe readily utilized to accurately position and implant the bone pluggraft. Further, the securement approach provides for detachment andremoval of the surgical instrument while the bone plug graft remainswithin the body.

More particularly, the present invention provides in one aspect, asurgical instrument for positioning an osteochondral plug within a bonedefect site. The surgical instrument includes an elongate shaft havingproximal and distal ends which define a longitudinal axis extendingtherebetween. The distal end of the elongate shaft is configured andshaped to allow intimate contact with the osteochondral plug. Further, aribbon extends along the sides of the elongate shaft and forms a loop atthe distal end of the elongate shaft. When in use, the loop isappropriately sized to secure the osteochondral plug to the distal endof the elongate shaft.

The present invention provides in another aspect, a surgical instrumentthat includes an elongate shaft having proximal and distal ends thatdefine a longitudinal axis extending therebetween. The distal end of theelongate shaft is configured to contact the osteochondral plug. Thesurgical instrument also includes a ribbon that extends along the sidesof the elongate shaft and forms a loop at the distal end of the elongateshaft. During use of the surgical instrument, the loop is sized to holdand secure the osteochondral plug to the distal end of the elongateshaft. Further, the surgical instrument has an elongate sleeve thatincludes proximal and distal ends with a longitudinal axis extendingtherebetween. The elongate sleeve surrounds the elongate shaft,facilitating the holding of the ribbon in place relative to the elongateshaft. In addition, the surgical instrument includes a locking mechanismthat is positioned near the proximal end of the elongate shaft andfunctions to secure the ribbon to the elongate shaft when the lockingmechanism has be placed in a locked position.

Another aspect of the present invention provides a method for graspingan osteochondral plug. The method includes the step of employing asurgical instrument having an elongate shaft with proximal and distalends that define a longitudinal axis extending therebetween. The distalend of the elongate shaft is configured to contact the osteochondralplug. Also included in the surgical instrument is a ribbon extendingalong the elongate shaft that forms a loop at the distal end of theelongate shaft that is sized to receive the osteochondral plug. Furtherincluded in the surgical instrument is a locking mechanism that islocated near the proximal, end of the elongate shaft. The methodincludes the steps of placing the osteochondral plug within the loop ofthe ribbon and then pulling or providing tension to the one of the endsof the ribbon so to adjust the length of the ribbon and size of theloop, causing the loop to tighten around the osteochondral plug. Themethod includes the further step of engaging the locking mechanism tosecure the ribbon relative to the elongate shaft, resulting in thefixation of the osteochondral plug to the distal end of the elongateshaft.

The present invention provides in yet another aspect a method forpositioning an osteochondral plug within a bone defect, the methodincludes the step of obtaining a surgical instrument that has anelongate shaft with proximal and distal ends, the distal end beingconfigured to contact an osteochondral plug. The surgical instrumentalso includes a ribbon extending along the elongate shaft to form a loopat the distal end of the elongate shaft, the loop being sized to holdand secure the osteochondral plug to the distal end of the elongateshaft. Further, the surgical instrument includes a locking mechanismlocated near the proximal end of the elongated shaft for use in lockingthe ribbon relative to the elongate shaft and fixing the size of theloop, thereby securing the osteochondral plug to the distal end of theelongate shaft of the surgical instrument. The method also includes thesteps of employing the surgical instrument to implant the osteochondralplug within the bone defect. The method provides for the implantationand then, removing the surgical instrument and ribbon from the bonedefect site, leaving the osteochondral plug intact within the bonedefect.

Yet another aspect of the present invention provides a method offabricating a surgical instrument for facilitating the positioning of anosteochondral plug within a bone defect, the method includes the step ofproviding an elongate shaft with proximal and distal ends with alongitudinal axis extending therebetween. The distal end of the elongateshaft is configured to contact an osteochondral plug. The method alsoincludes the step of providing a ribbon that extends along the elongateshaft and forms a loop at the distal end of the elongate shaft. The loopis sized and dimensioned to allow for the insertion and holding of theosteochondral plug. A further step of the method is providing anelongate sleeve that includes proximal and distal ends and alongitudinal axis extending therebetween. The elongate sleeve surroundsthe elongate shaft facilitating holding the ribbon in place along thelongitudinal axis of the elongate shaft. The method also includes thestep of providing a locking mechanism positioned adjacent to theproximal end of the elongate shaft for selectively locking the ribbonrelative to the elongate shaft.

Further, additional features and advantages are realized through thetechniques of the present invention. Other embodiments and aspects ofthe invention are described in detail herein and are considered a partof the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features, andadvantages of the invention are apparent from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is an isometric view of one embodiment of a surgical instrument,shown with a ribbon securing an osteochondral plug to a distal end of anelongate shaft, in accordance with an aspect of the present invention;

FIG. 2 is an isometric, exploded view of the surgical instrument of FIG.1, in accordance with an aspect of the present invention;

FIG. 3 is a cross-sectional, side elevational view of the surgicalinstrument of FIG. 1, taken along line 3-3, in accordance with an aspectof the present invention;

FIG. 4 is an isometric view of the surgical instrument of FIG. 1positioned adjacent to a distal condyle of a human femur with anelongate sleeve in an extended position, and an osteochondral plug isattached to the distal end of an elongate shaft, shown prior toimplanting the osteochondral plug within a bone defect, in accordancewith an aspect of the present invention;

FIG. 5 is an isometric view of the surgical instrument of FIG. 4positioned adjacent to the distal condyle, shown with the elongatesleeve in a retracted position, and the osteochondral plug (attached tothe distal end of the elongate shaft) positioned within the condylarbone defect, in accordance with an aspect of the present invention; and

FIG. 6 is an isometric view of the surgical instrument of FIGS. 4 & 5positioned adjacent to the distal condyle, shown with the elongatesleeve in the retracted position following cutting and partialwithdrawal of the ribbon from the bone defect site, with theosteochondral plug remaining intact within the bone defect, inaccordance with an aspect of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Generally stated, disclosed herein is a surgical tool and a method forfacilitating the positioning and implantation of (for example) anosteochondral bone plug into a bone defect located in the distal aspectof a femoral condyle. Further described herein is a method for attachingan osteochondral bone plug to a surgical tool without damaging thearticular cartilage of the osteochondral plug graft. Also describedherein is a method for positioning an osteochondral plug within a bonedefect, and a method for fabricating a surgical instrument for use inpositioning an osteochondral plug within a bone defect site.

One embodiment of a surgical instrument 10, in accordance with an aspectof the present invention, is illustrated in FIGS. 1-3 and describedbelow.

As shown in FIG. 1, surgical instrument 10 includes an elongate shaft 20that has a proximal end 21 and a distal end 22 with a longitudinal axisextending therebetween. Distal end 22 of elongate shaft 20 is shaped tocontact the articular cartilage portion of an osteochondral bone pluggraft 50 without damaging the articular cartilage surface of the graft.The surface of distal end 22 is generally planar, though otherconfigurations, including convex and concave surfaces, are contemplatedherein to ensure intimate and non-damaging contact and securement ofosteochondral plug 50. The shaft portion 23 of elongate shaft 20 has agenerally oblong cross-section with opposing flat sides 24 extendingtypically the entire length of elongate shaft 20 including through theinner portion of proximal end 21 (see FIG. 3). The cross-section ofelongate shaft 20 is sized to allow for insertion of the shaft into acenter bore 35 of elongate sleeve 30. Positioned proximate to proximalend 21 is a rectangular shaped passage 25 that passes completely throughthe center of shaft portion 23. Passage 25 is appropriately sized anddimensioned to receive a press-fit spring 52 for use as part of acoupling mechanism 51. Proximal end 21 of elongate shaft 20 has acylindrical outside configuration that is constructed with a diameterthat is usually larger than the oblong cross-section of shaft portion23. The cylindrical outer configuration of proximal end 21 slidinglyengages a correspondingly generally cylindrical shaped clamp 56 that maythen be attached to proximal end 21 utilizing a clamp pin 26.

As seen in FIG. 2, clamp pin 26 is constructed to a length that allowsfor it to be press-fit and secured within a transverse hole 27 having alength that extends diametrically through the one external wall 28 ofclamp 56 and continuing through proximal end 21 exiting the opposingsecond external wall 28 of clamp 56. Also depicted in FIG. 2 is a notch29 positioned on one of the flat sides 24 of shaft portion 23. Notch 29may be oriented to align with a transverse slot 33 located within asidewall 34 of the elongate sleeve 30. Notch 29 in combination with slot33 allows the user of surgical instrument 10 to sever the ribbon 40through slot 33 following final positioning and implantation ofosteochondral bone plug graft 50.

Surgical tool 10 further includes an elongate sleeve 30 that has aproximal end 31, a distal end 32 and as described above, a transverseslot 33 positioned along a sidewall 34 and oriented about normalrelative to the longitudinal axis extending between proximal end 31 anddistal end 32. Elongate sleeve 30 is generally cylindrical in shape andincludes center bore 35. Center bore 35 is sized and dimensioned tosurround shaft portion 23, preferably functioning to protect andmaintain alignment of ribbon 40 along flat sides 24 of the elongateshaft. Transverse slot 33 penetrates sidewall 34 and providesvisualization of center bore 35 and ribbon 40. Further, the width oftransverse slot 33 is large enough to accommodate standard surgicalcutting tools, thereby allowing the user to cut any material that passesbeneath slot 33.

As shown in FIGS. 1 and 2, the external surface 37 of proximal end 31radially expands to allow for ease of use by the user when elongatesleeve 30 is moved from an extended position to a retracted positionduring the implantation of osteochondral plug 50. It should beunderstood to those skilled in the art that the shape and configurationof external surface 37 of proximal end 31 is for example purposes onlyand that other more ergonomically designed configurations may beconsidered for use in surgical instrument 10. As depicted in FIGS. 2 and3, a sleeve pin 53 is constructed to a length that allows for it to bepress-fit and secured within a second transverse hole 36. Transversehole 36 has a length that extends diametrically through sidewall 34,exiting out the opposing sidewall 34 of elongate sleeve 30. During theassembly process, sleeve pin 53 is inserted through transverse hole 36after elongate sleeve 30 has been slid into place over shaft portion 23.Following insertion, the ends of sleeve pin 53 are in contact with thetwo diametrically opposed sidewalls 34. The center section of sleeve pin53 is positioned within passage 25 and interfaces with one end of spring52. Coupling mechanism 51 of surgical instrument 10 preferably includes,in combination, the inserted sleeve pin 53 and spring 52. Uponmechanically coupling elongate sleeve 30 to elongate shaft 20 viacoupling mechanism 51, elongate sleeve 30 is spring-biased relative toelongate shaft 20 and may be moved from an extended position to aretracted position.

As seen in FIG. 4, elongate sleeve 30 is oriented in the extendedposition with distal end 22 of elongate shaft 20 and distal end 32 ofelongate sleeve 30 being substantially adjacent and parallel relative toeach other. Elongate sleeve 30 is shown in FIG. 5 in the retractedposition which allows the user of surgical instrument 10 to observe theposition of osteochondral plug 50 when inserting the plug into a bonedefect 61 before osteochondral plug 50 has been detached from surgicalinstrument 10. The user of surgical instrument 10 may move elongatesleeve 30 into the retracted position several times during theimplantation procedure in order to ensure that proper placement ofosteochondral plug 50 within bone defect 61 and the surrounding surfacecontour of the femur 60 has been achieved.

FIGS. 1 and 3 depict ribbon 40 positioned with surgical instrument 10,securing osteochondral plug 50 to distal end 22. Ribbon 40 includes afirst end 41, a second end 42 with a narrow band-like structure 43extending between the two ends. The overall length of ribbon 40 variesdepending upon the application of use and the size of surgicalinstrument 10. Typically, ribbon 40 may come in a plurality ofthicknesses dependent upon material quality, composition and use insitu. As shown in FIG. 1, ribbon 40 is fabricated from a substantiallyflexible and inert material. Materials that may be used formanufacturing of ribbon 40 include, but are not limited to UHMWpolyethylene, thermoplastic polymers, thermosetting polymers, ferrousmetals, non-ferrous metals, elemental metals, metal alloys, fiberreinforced materials, carbon based materials, Mylar®, Teflon®, PEEK, ABSpolymers, polyethylene terephthalate, polyester film, polyester fiber,tetrafluroethylene polymer, fluoro polymers, fluorocarbon resins, TFEcopolymers, polytetrafluroethylene and polyamides. Also, the ribbon canbe made out of a natural fiber or combination of fibers such as nylon,Dacron®, Gore-Tex® and cotton. Further, ribbon 40 may be constructed ofa biologic material such as Type I collagen, Type II collagen, Type IVcollagen, fibrin, hyaluronan, alginate, chitosan, gelatin, agarose,cell-contracted collagen containing proteoglycans, glycosaminoglycans orglycoproteins, polymers of aromatic organic acids, fibronectin, laminin,bioactive peptide growth factors, cytokines, elastin, fibrin, syntheticpolymeric fibers made of poly-acids such as polylactic, polyglycolic orpolyamino acids, polycaprolactone, absorbable epsilon caprolactonepolymer, polypeptide gel, copolymers thereof and combinations thereof.As stated above, ribbon 40 is biocompatible, biodegradable, flexiblehydrophilic, non-reactive, has a neutral charge and is able to have orhas a defined shape and structure.

As shown in FIGS. 1, 4, 5 and 6, ribbon 40 is generally sized with awidth W that is equal or smaller than the width D of osteochondral plug50. The basis for this size relationship is because width W of ribbon 40must be equal to or less than width D of osteochondral plug 50 to allowfor accurate and intimate placement of osteochondral plug 50 within bonedefect 61. In the event width W is greater than width D, the close fitnecessary for the bone graft to integrate with the host defect site willlikely not occur because of possible interference of the edges of ribbon40 with the side walls of bone defect 61 and the sides of osteochondralplug 50. Further, the width size relationship is important tofacilitating removal of ribbon 40 following final placement ofosteochondral plug 50 within bone defect 61. Osteochondral plug 50 istypically square or rectangular shaped, though it should be understoodto those skilled in the art that other shapes are contemplated and maybe utilized when forming the outside configuration of osteochondral plug50, including, but not limited to oval, oblong, circular or derivationsof these non-polygonal shapes, as well as triangular, hexagonal andother polygonal shapes.

As shown in FIGS. 1 and 3, when ribbon 40 is secured within surgicalinstrument 10 extending along flat sides 24, band 43 forms a loop 44 atdistal end 22 of elongate shaft 20. The size of loop 44 is dependentupon the size of osteochondral plug 50 and the amount of tension that auser places on ribbon 40 following insertion of osteochondral plug 50within loop 44. Prior to use in positioning osteochondral plug 50 withinbone defect 61, first end 41 is fixed in place at proximal end 21 ofelongate shaft 20 by the clamp 56. Ribbon 40 is located along one flatside 24 of elongate shaft 20, around distal end 22 and then up theopposing flat side 24. Second end 42 is passed through an internal slot59 positioned within clamp 56, exiting out of proximal end 21. Loop 44is formed by placing tension on band 43 at distal end 22, thereby urgingband 43 to slide in a distal direction resulting in an increase in loop44 size. Loop 44 size is fixed by engaging locking mechanism 54 in alocked position and securing the position of second end 42 and thelength of band 43. Preferably, fixing the size of loop 44 usually occursafter osteochondral plug 50 is placed between loop 44 and distal end 22with second end 42 being pulled to tighten loop 44 around osteochondralplug 50 and firmly hold osteochondral plug 50 against distal end 22.Following the tightening of ribbon 40, locking mechanism 54 is actuatedfrom an unlocked position to a locked position.

FIG. 2 depicts locking mechanism 54 disposed at proximal end 21. Lockingmechanism 54 typically includes a bolt 55 and clamp 56. Bolt 55 (i.e.,one example of the locking member), may comprise a handle portion 63with a threaded post 64 extending from the undersurface of handleportion 63. Clamp 56 is (in one embodiment) a unitary cylindrical bodywith a non-through central lumen 65 at one end of clamp 56 and acentralized generally smaller threaded hole 58 located at the oppositeend. As described above, clamp 56 and elongate shaft 20 are connectedfollowing the insertion of proximal end 21 into a central lumen 65.Clamp pin 26 is then inserted into transverse hole 27 securing clamp 56to proximal end 21. As seen in FIG. 3, clamp 56 further includesinternal slot 59 through which second end 42 passes before exitingthrough the proximal end of clamp 56. Locking mechanism 54 is in anunlocked position when threaded post 64 of bolt 55 is loosely threadedinto threaded hole 58. When locking mechanism 54 is in the lockedposition, threaded post 64 fully engages threaded hole 58 until theundersurface of handle portion 63 abuts the proximal surface of bolt 55securing second end 42 of ribbon 40 therebetween. First end 41 remainsgenerally fixed by clamp 56 when locking mechanism 54 is in both lockedand unlocked positions.

The method for securing an osteochondral plug graft to a surgicalinstrument includes obtaining a surgical instrument 10 which includeselongate shaft 20 with distal end 22 shaped and configured to contactosteochondral plug 50. Surgical instrument 10 also includes ribbon 40that extends along opposing flat sides 24 of elongate shaft 20. Ribbon40 forms loop 44 to accommodate osteochondral plug 50 at distal end 22.Further included in the construct of surgical instrument 10 is lockingmechanism 54 that is typically disposed at proximal end 21 of elongateshaft 20. Locking mechanism 54 secures ribbon 40 in place relative toelongate shaft 20 to maintain the appropriate sized loop 44 at distalend 22 when in a locked position (as described above). The methodfurther includes placing osteochondral plug 50 within loop 44 andapplying tension via second end 42 to adjust the overall length ofribbon 40, thereby causing loop 44 to tighten around osteochondral plug50 and secure osteochondral plug 50 to distal end 22. It should beunderstood that the method may include engaging locking mechanism 54 toa locked position (as described above) in order to fix ribbon 40 andloop 44 size relative to elongate shaft 20 resulting in the securementof osteochondral plug 50 to distal end 22.

The method for positioning an osteochondral plug graft within a femoraldistal condyle bone defect includes obtaining a surgical instrument 10including elongate shaft 20 with distal end 22 shaped and configured tocontact osteochondral plug 50. Surgical instrument 10 typically hasribbon 40 that extends along opposing flat sides 24 of elongate shaft 20forming a loop 44 at distal end 22 that is sized to receiveosteochondral plug 50. Surgical instrument 10 includes locking mechanism54 that is typically disposed at proximal end 21 of elongate shaft 20.Locking mechanism 54 when actuated to a locked position locks ribbon 40relative to elongate shaft 20 to maintain the appropriately sized loop44 at distal end 22, resulting in the securement of osteochondral plug50 to distal end 22.

As shown in FIG. 4, the method further includes positioningosteochondral plug 50, while secured to surgical instrument 10, intobone defect 61 located in a distal condyle of femur 60. As shown in FIG.5, elongate sleeve 30 may be moved to a retracted position, allowing theuser to see the position and orientation of bone plug 50 within bonedefect 61. In the event osteochondral plug 50 is not placed in asatisfactory position, the user may withdraw osteochondral plug 50 fromthe host defect site and reorient osteochondral plug 50 and attempt toimplant osteochondral plug 50 again. The securement mechanism utilizedwith surgical instrument 10 allows the user to reposition the plug graftnumerous times without damaging either the host bone site orosteochondral plug 50.

As depicted in FIG. 6, following final placement of osteochondral plug50 by the user, band 43 of ribbon 40 is severed through slot 33 inelongate sleeve 30. The user loosens bolt 55 to release end 42 allowingribbon 40 to be pulled proximally along flat side 24 and exiting fromsurgical instrument 10 at the proximal end of clamp 56. Followingribbon's 40 withdrawal from beneath implanted osteochondral plug 50 andout of bone defect 61, osteochondral plug 50 is left implanted withinthe host site and surgical instrument 10 is then typically moved awayfrom femur 60.

A method for fabricating a surgical instrument that is to be used forpositioning a plug graft within a bone defect site includes providingelongate shaft 20 that includes proximal end 21 and distal end 22,wherein distal end 22 is designed to contact and protect osteochondralplug 50. Further, surgical instrument 10 is fabricated by providing,typically, ribbon 40 that extends along opposing flat sides 24 of shaftportion 23 to form loop 44 at distal end 22. Loop 44 is generally sizedto capture osteochondral plug 50. Additionally, surgical instrument 10is fabricated by providing elongate sleeve 30 that has proximal anddistal ends 31, 32. When assembled, elongate shaft 20 is slid intocenter bore 35 of elongate sleeve 30 resulting in elongate sleeve 30surrounding shaft portion 23 and ribbon 40. Elongate sleeve 30preferably functions to maintain position of ribbon 40 along flat sides24 of shaft portion 23 as well as acting to protect ribbon 40. Surgicalinstrument 10 is also fabricated by providing locking mechanism 54located at proximal end 21 of elongate shaft 20. Locking mechanism 54 isconfigured to actuate between a locked position and an unlockedposition. When in the locked position, locking mechanism 54 locks ribbon40 in a fixed position relative to elongate shaft 20 by securing secondend 42. Locking mechanism 54 includes (in one embodiment) bolt 55 andclamp 56, with bolt 55 threadingly engaging threaded hole 58 disposed inproximal end of clamp 56.

Although preferred embodiments have been depicted and described indetail herein, it will be apparent to those skilled in the relevant artthat various modifications, additions, substitutions and the like can bemade without departing from the spirit of the invention and these aretherefore considered to be within the scope of the invention as definedin the following claims.

1-44. (canceled)
 45. A method of grasping an osteochondral plug, themethod comprising: employing a surgical instrument comprising anelongate shaft with proximal and distal ends, and a longitudinal axisextending therebetween, the distal end of the elongate shaft beingconfigured to contact an osteochondral plug; a ribbon extending alongthe elongate shaft and forming a loop at the distal end of the elongateshaft, wherein when in use, the loop is sized to receive theosteochondral plug to the distal end of the elongate shaft; an elongatesleeve having a proximal and a distal end, and a longitudinal axisextending therebetween, wherein the elongate sleeve surrounds theelongate shaft and facilitates holding the ribbon in place relative tothe elongate shaft; and a locking mechanism disposed near the proximalend of the elongate shaft for locking the ribbon relative to theelongate shaft when in a locked position, wherein the locking mechanismincludes a clamp and a rotatable bolt mounted to the clamp, therotatable bolt being longitudinally movable between a proximal unlockedposition wherein the ribbon is not locked and a distal locked positionwherein the bolt engages and secures an end portion of the ribbonbetween a surface of the bolt and a proximal surface of the clamp,wherein the ribbon includes a first end portion secured by the clampwhen the bolt is in the proximal unlocked position and in and oppositethereto, a second end portion which is releasably secured by the bolt;placing the osteochondral plug within the loop of the ribbon; pullingone end of the ribbon to adjust a length of the ribbon and thereby sizeof the loop to tighten the loop around the osteochondral plug; andengaging the locking mechanism to secure the ribbon relative to theelongate shaft and thereby secure the osteochondral plug to the distalend of the elongate shaft.
 46. The method of claim 45, wherein theemploying comprises disposing the ribbon along opposing sides of theelongate shaft and forming the loop at the distal end thereof to securethe osteochondral plug to the distal end of the elongate shaft.
 47. Themethod of claim 45, further comprising providing the osteochondral plugwith a width D, and wherein the ribbon comprises a width W, whereinwidth W is equal to or less than width D.
 48. The method of claim 45,wherein the employing further comprises providing the locking mechanism,the locking mechanism comprising a locking member threadably coupled tothe proximal end of the elongated shaft for securing the ribbon relativeto the elongate shaft when in a locked position, and wherein when in anunlocked position, the locking mechanism allows for removal of theribbon from the elongate shaft.
 49. The method of claim 45, wherein theemploying further comprises providing the elongate shaft with at leastone of a planar surface, a convex surface and a concave surface.
 50. Themethod of claim 45, wherein the ribbon comprising a substantiallyflexible, biocompatible material.
 51. The method of claim 45, whereinthe ribbon is fabricated from at least one of UHMW polyethylene,thermoplastic polymer, thermosetting polymer, ferrous metal, non-ferrousmetal, elemental metal, metal alloy, fiber reinforced material, carbonbased material, PEEK, ABS polymers, nylon, polyethylene terephthalate,polyester film, polyester fiber, tetrafluroethylene polymer, fluoropolymers, fluorocarbon resins, TFE copolymers, polytetrafluroethyleneand polyamides.